The present invention generally relates to automatic grade crossing gate systems and more particularly to a system and method for electronically controlling and monitoring a grade crossing gate system.
Grade crossing gate systems are common means of warning and controlling approaching traffic at a highway-rail grade crossing or road-road crossing. Grade crossings where streets and railroad tracks intersect are notorious for collisions between roadway and rail vehicles. Various types of grade crossing warning systems are used to alert pedestrians and roadway vehicle operators about the presence of an oncoming train. Passive warning systems include signs and markings on the roadway that indicate the location of the crossing. Active warning systems include an audible signal from a locomotive horn and various types of wayside warning systems. Some of the grade crossing warning systems are activated by an approaching train and may include visual and audible alarms as well as physical barriers.
Typically, grade crossing warning systems are subject to normal equipment reliability and operability concerns. Reliable operation of such equipment is important for the safety of locomotives, vehicles and human life. In order to reduce the likelihood of equipment failures, routine maintenance and inspections are performed on grade crossing warning equipment. In particular, an inspector visits the site of each crossing periodically to inspect the equipment and to confirm its proper operation. Unexpected failures may occur in spite of such efforts, and such failures may remain undetected for a period of time.
Presently deployed grade crossing warning systems, such as, for example, the system illustrated in FIG. 1 mostly employ a mechanical arrangement to control a motor for opening and closing a gate arm. FIG. 1 shows an elevation view of a railroad crossing gate 10, which includes a mast or pole 14 having a base 16, which is securely fastened to a concrete foundation 18. The mast 14 supports and carries a cross-arm 26 bearing the words “Railroad Crossing”, a warning bell 34, signal lamps 28. The mast 14 also supports and carries a controller unit 36 and an electrical junction box 38. Flexible connection 42 connects the controller 36 to the junction box 38. There is a series of warning lights 32 mounted on a gate arm 12. A counterweight 22 counteracts the weight of the gate arm 12 reducing the amount of mechanical power required of a motor in the controller 36 to raise and lower the gate arm 12, thereby making it feasible to use less-costly fractional or low horsepower motors. The gate arm 12 is coupled to a controller 36, which bi-directionally brakes the crossing gate arm travel movement. There is a pinion gear (not shown in the figure) inside the controller 36 that is driven by a motor. A main shaft 24 bearing a gear assembly runs through the controller 36. The pinion gear meshes with and drives a series of reduction gears. This gear assembly in turn drives the main output shaft 24, which in turn drives the gate arm 12 between its two extreme positions.
In a conventional system like this, typically a position detecting system is provided for detecting the position of the gate arm 12 during its motion. This type of position detecting system may take the form of cam operated contact fingers, a mercury level switch or any other type of system that is useful for determining the position of the gate arm 12. The cam operated contact fingers are in contact with the gate arm 12 or the gear teeth inside the controller 36. The mechanical cams' profiles are designed in such a way that as the gate arm 12 moves, the mechanical contacts are closed and opened at appropriate intervals to activate different warning systems e.g. lights 32, and bell 34, etc. The mechanical cams and the switches are located inside the controller unit 36. The controller 36 is activated by a remote control unit or a wayside bungalow 44 with its own control unit 46. Flexible connection 48 connects the remote control unit 44 to the junction box 38.
Mechanical wear and tear of different subsystems and components as well as the chance of breakage and fracture of the gate arm 12 put a limit on the reliability and operability of the system shown in FIG. 1. Moreover, periodic manual inspection of grade crossing gate systems per Federal Railroad Administration (FRA) regulations is an expensive process. Moreover, a problem with manually inspecting this type of grade crossing gate system is that it is expensive to send a maintenance engineer out to all of the sites that have such a system to do an inspection on a yearly or monthly basis. Also, faults in the system sometimes are not noticed in a timely manner; sometimes not until an accident has occurred.
In order to overcome the above-mentioned problems, there is a need for an approach that can automate the control and monitoring of the railroad grade crossing gate systems, especially by communicating with a remote site. With approximately 60,000 railroad crossings with active warning systems in the United States, the ability to remotely monitor would improve safety since problems in the grade crossing gate system could be reported as they occur and fixed very soon thereafter. Cost, time and effort associated with inspection of the railroad crossing grade crossing gate systems would likely decrease because maintenance engineers would not have to go to each crossing site to inspect grade crossing gate systems; only to the ones that were noted as faulty.